A new electroencephalogram classification with reduced recording time in asphyxiated term infants

Conventional electroencephalogram (cEEG) is a reliable predictor of outcome in term infants with hypoxic ischemic encephalopathy (HIE). Early therapeutic hypothermia initiated within 6h after birth is a beneficial treatment in these infants. However, a classification system with reduced cEEG recording time to determine early intervention has not been reported. The aim of this study is to propose a new classification of depression on cEEG with reduced recording time in infants with HIE and to examine the correlation between the classification and short-term outcome.

We retrospectively investigated 20 term infants with HIE in whom cEEG was performed within 12h after birth, and deaths or outcomes at 18months of age were assessed. We determined grades 0-3 EEG depression in each 10-min epoch based on the most common EEG patterns of each 20s epoch defined by our criteria.

Eighteen infants could be assessed by depression grade. The Spearman's rank correlation coefficient Rs between the maximum depression grade in 10-min epochs and three-grade outcomes was 0.68 (P=0.002), and that between the minimum one and outcomes was 0.66 (P=0.003). The area under the receiver operating characteristic curve of the maximum and minimum depression grades for predicting abnormal outcome were 0.885 and 0.869, respectively.

We demonstrated a new cEEG depression classification with a recording time of at least 10min in term infants with HIE and a good correlation with short-term outcome.